docs: def contraction_round_Miller(Di1, Di2, rc):
      r'''Returns loss coefficient for any round edged pipe contraction
      using the method of Miller [1]_. This method uses a spline fit to a graph
      with area ratios 0 to 1, and radius ratios (rc/Di2) from 0.1 to 0.
  
      Parameters
      ----------
      Di1 : float
          Inside diameter of original pipe, [m]
      Di2 : float
          Inside diameter of following pipe, [m]
      rc : float
          Radius of curvature of the contraction, [m]
  
      Returns
      -------
      K : float
          Loss coefficient in terms of the following pipe, [-]
  
      Notes
      -----
      This method normally gives lower losses than the Rennels formulation.
  
      Examples
      --------
      >>> contraction_round_Miller(Di1=1, Di2=0.4, rc=0.04)
      0.08565953051298639
  
      References
      ----------
      .. [1] Miller, Donald S. Internal Flow Systems: Design and Performance
         Prediction. Gulf Publishing Company, 1990.
      '''
      A_ratio = Di2*Di2/(Di1*Di1)
      radius_ratio = rc/Di2
      if radius_ratio > 0.1:
          radius_ratio = 0.1
      Ks = float(bisplev(A_ratio, radius_ratio, tck_contraction_abrupt_Miller))
      # For some near-1 ratios, can get negative Ks due to the spline.
      if Ks < 0.0:
          Ks = 0.0
      return Ks